How can I check to see if a '97-2000 4X4 has a limited slip diff. ?


thanks....

 

The quickest way is to look at the axle code on the sticker inside the driver's side door jamb.

 

Even quicker, mash the gas to the floor and look in the rearview mirror, two marks means limited slip.....
Of course the clutches may be worn on a 97....

 

Doesn't necessarily mean anything. I had a 240SX with an open rear end that would leave two black marks if I did it right.

 

I've never seen an open diff spin both tires. Doesn't make sense....
There are no clutches or locking mechanism to keep both wheels driving, right?

 

Look at the axle code on the door post. If it has 2 numbers it's an open diff. If it has a letter and number it's LS.
H9=3:55 ls
B6=3:73 ls
B5=4:10 ls

 

Jack up both rear tires and with the truck in neutral, spin one tire by hand. If the tire on the other side spins in the SAME direction...you have LS. If it spins in the opposite direction...you have an open rear.

Sidewinder

 

Usually whenever I made it do it, I backed up a little bit before I threw it in first and put the hammer down. I guess it made the differential bind up just enough to send torque to both axles. I dunno the science behind it. Also, I've seen limited slip rear ends not actually limit any slipping at all, and act just like an open rear end.

 

Interesting, I guess that's possible. I guess as long as you somehow keep the torque equal between the wheels they will both drive. When the clutches wear out in a LS you will get the open diff action, or if you overcome the max torque difference the clutches will release.

 

Thanks, Jim. just what I was after

 

I'm not so sure about that. I would buy that for a locker but not for a LS with the clutch packs. Correct me if I'm wrong but one wheel must spin more than the other before the clutches lock up meaning that before that happens it will act as an open diff. For sure the axle codes are the easy way to go short of dropping the diff pan.

 

Isn't it the oppsite, it acts like a locker until a certain torque difference is met and then it opens. That way when you are taking a corner and one wheel is turning faster than the other, the clutches disengage and you go around the corner with no wheel hop. The way you describe would cause the wheels to be locked around corners, defeating the purpose of a differential.

 

you have it backwards....

 

I wouldn't say backwards, the clutches aren't necessary if the wheels are turning the same speed, but the springs are still pushing the side gears against the clutches. Once one tire starts to turn faster the clutches fight that and try to keep both tires spinning at the same rate until the torque difference is too much for the clutch pack, then the wheels can turn at different rates, like when cornering. The torque required depends on the spring stiffness and the friction of the clutches.
A Torsen diff will act like an open diff until one wheel loses traction then the gears will bind and supply torque to the slower wheel, but that's not LS.

 

Yup, I guess that's how it happened in the crappy open diff I had. The LS in my truck seems to work fine, though I imagine that's because it seems like it had a pretty easy life before I got ahold of it. I will also say that you're right about Torsen diffs, and that based on my limited experience with them (from RX7s) I much prefer the way they act (open and then progressively binding the axles together) instead of the way an LS acts (binds and then all of a sudden the friction plates break loose and don't bind the axles anymore). It's much more confidence inspiring that the vehicle helps you along the harder you push it.